If you attempt to run a concurrent index creation in a transaction, Postgres will error. We should warn about this:
begin;
CREATE INDEX CONCURRENTLY IF NOT EXISTS idx_foo_bar ON account (foo);
-- Query 1 ERROR at Line 1: : ERROR: CREATE INDEX CONCURRENTLY cannot run inside a transaction block
If you attempt to run a concurrent index creation in a transaction, Postgres will error. We should warn about this:
based on #331